Okla. Stat. tit. 21 § 1115
Rape in the first degree is a felony punishable by death or imprisonment in the custody of the Department of Corrections, for a term of not less than five (5) years, life or life without parole. Except for persons sentenced to life or life without parole, any person sentenced to imprisonment for two (2) years or more for a violation of this section shall be required to serve a term of post-imprisonment supervision pursuant to subparagraph f of paragraph 1 of subsection A of Section 991a of Title 22 of the Oklahoma Statutes under conditions determined by the Department of Corrections. The jury shall be advised that the mandatory post-imprisonment supervision shall be in addition to the actual imprisonment. Any person convicted of a second or subsequent violation of subsection A of Section 1114 of this title shall not be eligible for any form of probation. Any person convicted of a third or subsequent violation of subsection A of Section 1114 of this title or of an offense under Section 888 of this title or an offense under Section 1123 of this title or sexual abuse of a child pursuant to Section 843.5 of this title, or any attempt to commit any of these offenses or any combination of these offenses shall be punished by imprisonment in the custody of the Department of Corrections for life or life without parole.
Okla. Stat. tit. 21, § 1115